Shear Wave Elastography Improves Specificity of Ultrasound for Parotid Nodules

Objectives This study aimed to determine the performance of Virtual Touch tissue quantification (VTQ) technique in the differential evaluation of parotid gland nodules. Methods Acoustic radiation force impulse VTQ technique was used to determine the shear wave velocity (SWV) of 76 patients with parotid nodules and 30 subjects with normal parotid gland. These nodules were assigned to benign and malignant nodules according to histopathology, measurements of SWV were compared, a cutoff point for benign and malignant nodules was obtained with reference to receiver-operating characteristic curve, and relevant sensitivity and specificity were evaluated. Results There were 61 of 76 patients with benign parotid nodules and 15 of 76 patients with malignant nodules. The SWV of the malignant nodules was higher than the SWV of the benign nodules, and the SWV of the benign and malignant nodules was higher than the normal parotid glands. There were significant differences between benign and malignant nodules as well as normal parotid glands in terms of the age and SWV of the nodules (all P < 0.001). The area under the curve is 0.893, the cutoff is 2.445 m/s, and the sensitivity and specificity are 80.0% and 91.8%, respectively. Conclusions Acoustic radiation force impulse VTQ technique can determine the stiffness of parotid nodules in general, its ability to distinct malignant from benign nodular nodule is still not strong, and overlay of SWV of VTQ between benign and malignant nodules is the main impedance to set cutoff point.